How to solve Go-Stomp read timeout

Question

Try subscribing ActiveMQ(Apollo) using Go-Stomp, but I am having a read timeout error. My app should be alive 24 hours per day to process the incoming messages.

Question :

Is there a way to keep the subscription although there is no more message existing in the queue? Trying to put ConnOpt.HeartBeat also does not seem to work
Why after the read timeout, it seems that I still accept one more message?

Below are my steps :

I put 1000 messages for testing in the input queue
Run a subscriber, code provided below
Subscriber finished reading 1000 messages After 2-3 seconds, saw error " 2016/10/07 17:12:44 Subscription 1: /queue/hflc-in: ERROR message:read timeout".
Put another 1000 messages, but it seems the subscription is already down, therefore no message is not being processed

My Code :

  var(
   serverAddr   = flag.String("server", "10.92.10.10:61613", "STOMP server    endpoint")
   messageCount = flag.Int("count", 10, "Number of messages to send/receive")
   inputQ       = flag.String("inputq", "/queue/hflc-in", "Input queue")
)

var options []func(*stomp.Conn) error = []func(*stomp.Conn) error{
   stomp.ConnOpt.Login("userid", "userpassword"),
   stomp.ConnOpt.Host("mybroker"),
   stomp.ConnOpt.HeartBeat(360*time.Second, 360*time.Second), // I put this but seems no impact
}

func main() {
  flag.Parse()
  jobschan := make(chan bean.Request, 10)
  //my init setup
  go getInput(1, jobschan)
}

func getInput(id int, jobschan chan bean.Request) {
   conn, err := stomp.Dial("tcp", *serverAddr, options...)

   if err != nil {
      println("cannot connect to server", err.Error())
      return
   }
   fmt.Printf("Connected %v \n", id)

   sub, err := conn.Subscribe(*inputQ, stomp.AckClient)
   if err != nil {
     println("cannot subscribe to", *inputQ, err.Error())
     return
   }

   fmt.Printf("Subscribed %v \n", id)
   var messageCount int
   for {
    msg := <-sub.C
    //expectedText := fmt.Sprintf("Message #%d", i)
    if msg != nil {

        actualText := string(msg.Body)
        
        var req bean.Request
        if actualText != "SHUTDOWN" {
            messageCount = messageCount + 1
            var err2 = easyjson.Unmarshal([]byte(actualText), &req)
            if err2 != nil {
                log.Error("Unable unmarshall", zap.Error(err))
                println("message body %v", msg.Body) // what is [0/0]0x0 ?
            } else {
                fmt.Printf("Subscriber %v received message, count %v \n  ", id, messageCount)
                jobschan <- req
            }
        } else {
            logchan <- "got some issue"
        }
    }
   }
  }

Error :

2016/10/07 17:12:44 Subscription 1: /queue/hflc-in: ERROR message:read timeout
[E] 2016-10-07T09:12:44Z Unable unmarshall
message body %v [0/0]0x0

score 1 · Accepted Answer · answered Oct 10 '16 at 03:47

Solved by adding these lines :

in Apollo, noticed that the queue deleted after being empty after several secs, so put auto_delete_after to several hours in apollo.xml , eg :

<queue id="hflc-in" dlq="dlq-in" nak_limit="3" auto_delete_after="7200"/>
<queue id="hflc-log" dlq="dlq-log" nak_limit="3" auto_delete_after="7200"/>
<queue id="hflc-out" dlq="dlq-out" nak_limit="3" auto_delete_after="7200"/>

in Go, noticed that go-stomp will just give up right after it can't found any message in queue, so in the conn options, add HeartBeat Error

var options []func(*stomp.Conn) error = []func(*stomp.Conn) error{
   //.... original configuration
   stomp.ConnOpt.HeartBeatError(360 * time.Second),
}

However still confused about the question no 2.

SolThoth · Answer 2 · 2021-12-18T22:37:37.667

regarding #2 I had the same problem as I wrap my process in an infinite loop. What I discovered was that on the "last message" you get the response from the channel subscription with an empty message, but contains the error of the timeout. This is to be able to gracefully handle the disconnect. Here is how I have it implemented on my apps

func process(subscription *stomp.Subscription) (error) {
    log.Println("Waiting for a message")
    msg := <- subscription.C
    if msg.Body != nil {
        log.Println("Message from the queue: ", string(msg.Body))
    } else {
        log.Println("message is empty")
        log.Println("error consuming more messages", msg.Err.Error())
        return msg.Err
    }
    return nil
}

How to solve Go-Stomp read timeout

2 Answers2